Keep in perspective that early 1900s to say 1950-70s, this was an ideological struggle – whether Jewish population will follow some of the Rabbis or follow some secular movements, whether Zionism, Bundism, or Communism. People had strong opinions about that. When you are trying to protect your community from the infectious ideology, you are not going to give them slack for still using Hebrew rather than Polish and Russian. In a long term, those who followed Zionists, fared better, both physically and spiritually, than those who followed other socialist movements.
Later on, it is more of an issue of interaction between different communities. If someone is leaving observance in our days, it is not because of Zionism, but of general secularism and of their teacher’s failures. So, we don’t need to re-fight those old wars.